Brandon McCarthy’s 2015 season will end with a perfect 3-0 record, a sketchy 5.87 ERA, and a right elbow with a ulnar collateral ligament tear that likely requires Tommy John surgery, the Dodgers were told before the opener of their three-game series against San Francisco.

The 31-year-old right-hander with a history of other shoulder issues still was signed to a four-year, $48 million free-agent contract in the off-season. The Dodgers’ due diligence with his medical history did not show anything to warrant concern about his elbow, although they did put some provisions in his current deal if something happened with his shoulder.

With the up-in-the-air return of No. 3 starting pitcher Hyun-Jin Ryu, out indefinitely with an inflamed shoulder but presumably due back in May, plus no guarantees with the health of left-hander Brett Anderson, who started Monday, the Dodgers had at least some reliability in McCarthy for four starts.

He gave up 15 earned runs, and a league-high nine homers, in 23 innings. He even became the first pitcher in major league history to give up four home runs with no walks and 10 strikeouts in a game. He kept his record clean and even picked up the win in Saturday’s 11-8 triumph at San Diego.

But in that last appearance, he essentially took himself out in the sixth inning while standing on the mound, telling the trainers he had tightness in his elbow. The ultrasound Monday showed the extent of the damage, which the Dodgers and McCarthy had anticipated would not be as severe as perhaps tendinitis.

Still, McCarthy and the disabled list are no strangers. He has been there 10 previous times since 2005, once because of a life-threatening brain hemorrhage. But none of them had to do with an elbow issue.

Andrew Freidman, the Dodgers’ first-year president of baseball operations, said before Monday’s game against the Giants he did not anticipate making any quick-fix trades to remedy McCarthy’s absence but will rely on an array of young arms at Triple-A Oklahoma City, some of whom have already been called up as spot starters, to get them through the next couple of months.

“Historically, April and May trades are pretty uncommon, and for the most part we are going to look inside,” Freidman said. “We have a number of interesting candidates. We’ll take some time and focus internally for now. It serves us well to get a feel for what we have. And then we’ll wake up June, scout other organizations in four-to-six weeks and figure out where to go from there.’

Freidman noted the recent big-league performances of Mike Bolsinger, Scott Baker and Carlos Frias, plus top prospect Zach Lee, who has gone 3-0 with a 0.95 ERA in 19 innings over three starts at Oklahoma City. There is also 19-year-old Julio Urias, currently at Double-A.

Baker is likely to remain in the rotation and start Friday or Saturday anyway. Kershaw is scheduled to start Tuesday, with Greinke on Wednesday before a day off Thursday that closes the month of April.

The Dodgers’ current DL also includes outfielder Yasiel Puig, closer Kenley Jansen, plus relief pitchers Joel Peralta, Brandon League and Chris Withrow, with starter Brandon Beachy (expected back in June as a possible rotation candidate). The 25-man roster as it stands has 13 pitchers with 12 position players.

“We still feel good about our club,” said manager Don Mattingly. “Someone just has to step forward and pitch well.”

Freidman said the plan is to just take it “turn by turn” and keep more of a focus actually on the bullpen, which could also be taxed more by rotation seat fillers.

“It always comes back to the bullpen because, ironically enough, this injury scares me more for the bullpen,” he said. “We have guys who can keep us in games, but I worry about the length they’re going to provide and the toll it is going to take on the bullpen. We have a deep bullpen at Triple-A, too, and will just have to continue to work series-to-series, and week-to-week to make sure we’re not putting our relievers in harm’s way in terms of how much work load they are taking on.”

For the moment, the Dodgers have McCarthy on the 15-day disabled list. To fill his roster spot, they recalled 27-year-old left-handed reliever Adam Liberatore from Oklahoma City.

McCarthy, an avid user of his Twitter account, told followers Monday: “To be fair, 31 years of use is a lot to ask for from a ligament.”

McCarthy said before Monday’s game that he would talk to more doctors about whether to go ahead with the ligament replacement surgery, but did not want to belabor the decision.

“I’d like to be back before the All-Star game (next season),” said McCarthy, who pitched 135 innings in 2013 with Arizona and a combined 200 innings — a career high — with the Diamondbacks and Yankees in 2014. “I hope I’m easily replaceable. I hope someone does well (taking his spot), but it just sucks that it’s at your expense.”

Tom Hoffarth is a freelancer. He had been with the Daily News/Southern California News Group since 1992 as a general assignment sports reporter, columnist and specialist in the sports media. He has been honored by the Associated Press for sports columnists and honored by the Southern California Sports Broadcasters Association for his career work. His favorite sportscaster of all time: Vin Scully, for professional and personal reasons. He considers watching Zenyatta win the Breeders' Cup 2009 Classic to be the most memorable sporting event he has covered in his career. Go figure that.